Burning
by Revhead
Summary: Castiel's stolen Grace is consuming him. He is going to die, he is sure of it. But when Dean offers him a way out, he realises there is more than one way to burn. Destiel, set after the season 9 finale.


**Burning**

Castiel had known this day was coming.

From the moment he absorbed the stolen Grace he had felt it burning, a flame licking away at his insides, consuming him. When the last ember of Grace died he knew he would die with it, crumbling to ash and dust, fading into nothing.

Castiel was resigned to his fate. He thought he might even welcome death and the peace it would bring.

But he had one last job to do. He had to save Dean Winchester.

He thought he could hold out long enough. He thought he could muster the strength he needed, or carry on through sheer force of will.

So when his time came, it was not the brutal explosion of pain as his Grace gave way and humanity returned that caused him to cry out in despair.

"_Father, it is not finished!_" Castiel screamed, desperate to be heard, to have his prayer answered just this once. "I need more time!" Fire lashed through him, taking him to his knees. "Father, please! Dean Winchester is not saved."

But he could feel his end approaching. The dark was creeping in, the cold had seeped into his bones, his every breath was a struggle. His life was draining away.

"Please, please let me save him."

God did not answer and the body of the angel Castiel collapsed into the dirt.

A single tear slid down his cheek.

His final whisper was one of grief, guilt and regret. His life's purpose, and he had failed. "I'm sorry, Dean."

Broken, defeated, Castiel closed his eyes and willed Death to come.

"Hey Cas."

Not Death.

"You called?"

_Dean_.

Castiel's eyes snapped open and he struggled to stand. His legs couldn't hold him, though, and he ended up sprawled on his back, gaping up at Dean like a fish out of water.

"Easy there, tiger," Dean smirked. He crouched down next to him. "Not doing too well, eh, Cas?"

"D-Dean…"

"In the flesh."

It hurt, to be so close, to have finally found him after all this time, but to know in the moment that mattered he was utterly powerless. Even if he had found a way to restore Dean's soul, there was nothing he could do now. He was going to die, and Dean would be damned.

"Dean, I'm s-sorry… I couldn't… save you."

Dean chuckled and shook his head. "I'm not the one who needs saving. I've seen mutilated corpses who look healthier than you."

"My…time…" Castiel exhaled.

"That's crap and we both know it. You're not ready."

Maybe that was true, but ready or not Death was coming for him. He should have been here already. "No…choice…"

"Normally you would be right about that, but normal rules have never really applied to us. How many times have you died now? 3? 4?"

"Think…for good…this time."

"Well sure, if you're just going to give up. Of course, there is another option…"

Cas frowned up at him, asking without words. Slowly, Dean began to smile.

"You're…offering me…a deal."

"What do you say, Cas? You could screw Death right in the face, take your life back, finally find out what this whole human deal is really all about. Live and love and do all of that other crap."

Cas stayed silent. Angels would usually pass into oblivion when they died. Dean made it sound like he was offering life, but Cas knew all too well how these deals ended. Hell hounds would come for him eventually and he would spend eternity in the Pt. There would be no peace, no end to his suffering.

"Up to you, buddy, but I could give you ten good years. Or you could die right here and now."

Ten years. To be honest, living had lost its appeal for Castiel. Maybe once life as a human had been what he wanted, but that was when he thought he would be sharing it with Dean. If Dean was lost to him, what reason did he have to continue on? It would be an empty, meaningless existence. That was not what he wanted.

"What do you want, Cas?" Dean asked, almost as though he could read Castiel's mind. It was disconcerting to be on the receiving end of such a knowing stare.

As Castiel gazed up into green eyes, he realised what he wanted. He wanted to save Dean. There was a chance that, if he took the deal, sometime during the next ten years he would find a way to restore Dean's soul. He could fulfil his life's purpose and give meaning to his existence.

If he succeeded, the sacrifice would be worth it. And if he failed, no torture in Hell could be equal to his anguish.

"Okay," Castiel gasped. "I'll do it."

"You'll sell your soul in exchange for 10 years of life on Earth?"

_In exchange for your soul,_ Cas thought. "Yes."

"You know you'll be human," Dean warned. "Your wings are not a part of this deal."

"I…understand."

"So we have a deal?"

"Yes."

Dean smiled. "Well then. Only one thing left to do." He shifted his weight so he was kneeling properly, then slid a hand under Castiel's neck and gently raised his head.

Castiel's breath hitched. He had forgotten about the kiss.

"Been waiting for this moment so long, baby," Dean murmured. He leaned in closer, breath ghosting across Castiel's skin. "Watching you, wanting you. Wanting to touch, to taste. And now I have you right where I want you."

Cas couldn't breathe. His heart was thumping so loudly he was sure Dean could hear it.

Was this just the demon talking? How much of the real Dean was left inside of him? Was it possible… had Dean really felt that way? Or was this all just a cruel trick?

Part of Castiel wanted to shy away, to escape while he could, but he remained frozen, staring wide-eyed up at the demon who wore Dean's face.

Dean moved in slowly, taking his sweet time, drawing out the moment.

His lips brushed oh-so-gently against Castiel's and lingered there, waiting for the answer to an unspoken question.

_Is this really what you want, Cas?_

Cas shuddered a breath against Dean's lips.

If he did this, there was no turning back.

He hesitated a moment longer.

The chaste almost-kiss turned abruptly violent as Castiel thrust his hands into Dean's hair and surged up to meet him. He crushed their mouths together, plunging his tongue past parted lips. It was hot, wet, messy, a clash of teeth and writhing of tongues. The desperate need for oxygen was ignored as they dragged air from each other's lungs, neither willing to give ground. Dean pressed in harder, nipping and sucking at Castiel's lips even as his hands slid down Castiel's back to drag his body full flush against him.

Castiel had never felt anything like this before. The heat, the intensity, the dizzying whirlwind of sensation. He was drowning yet burning, dying yet more alive than he ever had been. They kissed like the world was ending and there was nothing left in all of creation but this moment, infinitesimal yet infinite, the fallen angel and his demon.

Lightning cracked between them as the contract formed, binding and irreversible.

They broke apart, but Castiel keened at the loss of their connection and sought to recapture Dean's lips.

Dean's hand jerked back on Castiel's hair, blocking his advance. "Patience, Castiel. Not yet."

Castiel stared up at him, panting, reeling from the overload of emotion, unable to comprehend the rejection.

Dean smiled slow, a predator's gleam in his eyes. For an instant they flashed black, and Castiel remembered.

Dean was a demon.

Cas had just made a deal with the devil.

Dean leaned down, nuzzling intimately against Castiel's cheek before biting down on his earlobe hard enough to draw blood. "In ten years, baby," Dean whispered, "You're all mine."

Then Dean vanished, and Castiel collapsed into the dust.

Ruined. Empty.

Alone.


End file.
